Ore-concentrating process



UNITED STATES PATENT OFFICE.

WALTER A. SCOTT, 0F OAK PARK, ILLINOIS.

ORE-CONCENTRATING PROCESS.

No Drawing. Original application filed July 8, 1919, Serial No. 309,461.

filed December 15, 1920.

To all whom it may concern:

Be it known that I, WALTER A. Soon. a citizen of the United States, residing at Oak Park. in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Ore-Concentrating Processes, of which the following is a specification.

My invention is an improvement in the flotation process of concentrating ores when applied to ores which for eflicient treatment require the presence of acid but contain considerable quantities of acid-consuming substances such as calcium carbonate or other easily decomposable compound. This application is a division of my previously tiled application, Serial No. 309,461, filed July 8, 1919. The usual way of introducing acid is by admixture with the pulp and the acid added in this way becomes effective as a factor in the flotation process only after a quantity has been added in excess of that necessary to react with all of the easily decomposable carbonate or other substance present. A quantity of the acid is wasted which is substantially the chemical equivalent ot' the easily decomposable substance contained in the ore. It is to avoid all, or substantially all, of this waste that I have devised the method described herein.

In the treatment of ores of the type described above the effectiveness of the acid may be obtained by introducing it, preferably in gaseous form, in admixture with the bubble-forming air, hydrochloric and nitric acids being among those suitable for introduction in the gaseous form. By this means the acid is brought to the bubblewater interface Without coming into contact with and being uselessly consumed by the carbonate or other easily decomposable substance contained in the ore, and thereby the modifying effect of the acid is obtained with a minimum consumption thereof.

In that form of the flotation process in which the bubble-forming air is introduced Specification of Letters Patent.

Divided and this application Serial No. 481,010.

through a permeable medium submerged in the pulp a convenient mode of procedure when hydrochloric acid is used is to cause all or a part of the air to bubble through the aqueous solution of hydrochloric acid which is sold as commercial hydrochloric acid, or hydrochloric acid in the gaseous form, distilled from solution or derived from any source, may be directly mixed with the air before or at the time it reaches the rmeable medium. When the bubble-forming air is introduced into the pulp by agitation the upper part of the agitation cell may be inclosed except for an inlet opening through which the mixture of bubble-forming air and acid may be admitted thus forming above the pulp an atmosphere of the mixture which will be beaten into the pulp in the usual way. The economies and advantages incident to the procedure described herein are analogous to those obtained in that form of the flotation process in which the frothing and collecting agents, generally for convenience termed oils, are introduced in admixture with the bubble-forming air, but in the process described herein there is an added advantage in the avoidance of wasteful acid consumption.

I claim:

1. I11 the flotation process of concentrating ores containing acid-consuming ingredients and in the flotation concentration of which the presence of acid im roves the concentration. the operation of r ucing the ore to a freely-flowing pulp and introducing into said pulp a bubble-forming gas in admixture with an acid.

2. The process set forth in claim 1 further characterized by the use of acid in the gaseous form.

3. The process set forth in claim 1 further cha'acterized by the use of hydrochloric acl In testimony whereof, I have subscribed my name.

WALTER A. SCOTT. 

